Many automotive vehicles employ a braking system having a tandem master cylinder with dual compensation ports. The compensation ports provide brake fluid to the master cylinder from a reservoir. These braking systems also utilize anti-locking braking systems (ABS) in order to increase vehicle directional stability—in a braking condition. During ABS events, a pump is utilized to remove fluid from the wheel brake and return it to the master cylinder.
Unfortunately, the potential exists to damage the master cylinder during ABS control. As shown in FIG. 6, the tandem master cylinder 26 generally includes two pistons 11, 12 having lip seals 13, 14 for controlling the flow of brake fluid through the dual compensation ports 15, 16. When a sufficient amount of fluid is pumped from the wheel brake to the tandem master cylinder 10, high pressure fluid will force the lip seals 13, 14 past the dual compensation ports 15, 16, which in turn can cause damage to the lip seals.
One solution to this problem is to provide an additional accumulator downstream of the pump in order to prevent damage to the lip seals. Unfortunately, this additional hardware increases the weight of the braking system and also increases the systems cost. Accordingly, there exists a need to provide a braking system that prevents damage to the lip seals of a tandem master cylinder while minimizing the weight and cost of the braking system.